I love the Jacquie Lawson ecards - especially the doggy ones - but then they are so much better than most.
I still send cards but fewer than before - have deleted various very far-flung people who we're almost certainly never going to see again.
I do still like receiving them - they form part of our Christmas decorations, blu-tacked to various vertical surfaces.
Of the people I know well who've stopped sending them, I strongly suspect that they just CBA - which fair enough, since writing them can turn into quite a chore. But I know very well in those cases that it's not a question of money, and they could very easily afford the charity donations as well.
It'd be refreshing if anyone in such circs. would simply say they CBA, instead of giving worthy reasons about the planet and charity donations. Though I know very well that for a lot of people it is about the cost, especially the postage.